On Wed, Mar 06, 2024 at 10:15:44AM +0800, Z qiang wrote:
> >
> > synchronize_rcu() users have to be processed regardless
> > of memory pressure so our private WQ needs to have at least
> > one execution context what WQ_MEM_RECLAIM flag guarantees.
> >
> > Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
> > ---
> > kernel/rcu/tree.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> > index 475647620b12..59881a68dd26 100644
> > --- a/kernel/rcu/tree.c
> > +++ b/kernel/rcu/tree.c
> > @@ -1581,6 +1581,7 @@ static void rcu_sr_put_wait_head(struct llist_node *node)
> > /* Disabled by default. */
> > static int rcu_normal_wake_from_gp;
> > module_param(rcu_normal_wake_from_gp, int, 0644);
> > +static struct workqueue_struct *sync_wq;
> >
> > static void rcu_sr_normal_complete(struct llist_node *node)
> > {
> > @@ -1679,7 +1680,7 @@ static void rcu_sr_normal_gp_cleanup(void)
> > * of outstanding users(if still left) and releasing wait-heads
> > * added by rcu_sr_normal_gp_init() call.
> > */
> > - queue_work(system_highpri_wq, &rcu_state.srs_cleanup_work);
> > + queue_work(sync_wq, &rcu_state.srs_cleanup_work);
> > }
> >
> > /*
> > @@ -5584,6 +5585,9 @@ void __init rcu_init(void)
> > rcu_gp_wq = alloc_workqueue("rcu_gp", WQ_MEM_RECLAIM, 0);
> > WARN_ON(!rcu_gp_wq);
> >
> > + sync_wq = alloc_workqueue("sync_wq", WQ_MEM_RECLAIM, 0);
>
> Why was WQ_HIGHPRI removed?
>
I would like to check perf. figures with it and send out it as a
separate patch if it is worth it.
--
Uladzislau Rezki
